Eleven aviation groups, including the National Business Aviation Association (NBAA), recently expressed concern that a proposed cellular communications network will impact the satellite-based global positioning system (GPS) navigation capabilities.
The cellular network will operate within frequency bands used by GPS.
In February 2012, the Federal Communications Commission denied a planned cellular network because the cellular towers’ signals would interfere with aircraft navigation systems.
The company LightSquared, now called Ligado Networks, says it has limited the GPS disruptions within a 500-foot diameter around its towers.
In a letter to Daniel Elwell, Federal Aviation Administration acting director, the aviation groups doubt the risks have been mitigated.
Although Ligado’s plan has been changed since 2011, the groups said, the towers could still disrupt satellite phones or even more advanced technologies.
“There remain outstanding issues that call into questions the impacts such a system would have on airspace safety, specifically as it relates to both certified and uncertified GPS systems, continuity of navigation accuracy at low levels, and the effects on other safety of flight systems to include satellite communications,” the letter said.
Limiting disruptions to within a 500-foot diameter of the cellular towers does not address the aviation industry’s concerns, the letter said.